The invention concerns a method of distributing articles, especially such pieces of candy as slabs and bars of chocolate, pralines, etc., that are constantly arriving in transverse rows on a continuous conveyor to several packaging machines, whereby the articles are transferred one row at a time by means of a shunt to either an upstream or a downstream packaging machine, arrayed in a row on an outtake belt upstream of each packaging machine, and packaged in each packaging machine. The articles in question, particularly slabs of chocolate, are produced continuously in a manufacturing section and continuously supplied adjacent in transverse rows to the packaging section, which includes several machines. The total output of the packaging machines must be greater than that of the manufacturing section in order to create enough of a reserve output to ensure that the manufactured articles will continue being accommodated and packaged even during interruptions in processing, especially on the part of the packaging machines. Processing interruptions in the vicinity of the packaging machines are relatively frequent but necessitate relatively brief downtime. The different packaging machines must in fact be turned off almost regularly to allow regular replacement of the reels of packaging material and then readied again for operation. Processing interruptions can also occur in the vicinity of other systems, of the various belts and shunts for example in the event of undersized or broken slabs that should not be diverted to the packaging procedure, in which case appropriate detectors disengage the packaging machine or its associated shunt, etc. To compensate for these normal interruptions, which cannot be avoided, every packaging section is designed to operate with what is called a reserve output, meaning that the output of all the packaging machines is greater than that of the section that the pieces of candy are manufactured in. When all the packaging machines are operational, accordingly, it is possible either to keep one turned off to constitute a reserve output or to operate all at a reduced output.
The manufacturing section usually operates continuously, even during holidays and weekends. The packaging machines, however, must be turned off at such times because they require human supervision. The continuously manufactured articles must accordingly either be temporarily stored or will be rejected as excess upstream of the packaging section. Remelting such an excess and returning it to the manufacturing section is known. This approach, however, is impossible with filled candies. The only other possibility is to hire temporary help for the packaging section to keep the machines in continuous operation during weekends and holidays and handle the normal interruptions as they occur.
A method and packaging section of the aforesaid type is known from German Patent 2 831 323. Articles arrive constantly on a continuous conveyor. There is a shunt between the supply belt and the forwarding belt in the vicinity of each packaging machine. When it is in one state, the shunt leads to the forwarding belt and, when it is in the other state, to an outtake belt by way of other intermediate means of conveying. Since the outtake belt is at an angle of approximately 90.degree. to the supply belt and forwarding belt, a continuous row of articles can be constructed from several transverse rows on the outtake belt, supplied to the packaging machine, and packaged. When the packaging machine or outtake belt associated with it is not operational, the shunt will remain in a state wherein it transfers the articles from the supply belt to the forwarding belt. At the end of the forwarding belt is the supply belt associated with another packaging machine, accompanied by another shunt and another forwarding belt. Several packaging machines can accordingly be distributed to branch off next to one another in a conveyor. The forwarding belt associated with the last packaging machine can lead to an overflow that diverts articles that cannot be accommodated by the packaging machines as a whole. One drawback to this system is that it has no intermediate-storage capacity. The only ways of preventing excess are to turn off the manufacturing section when the personnel are off or to replace them with temporary workers.
Increasing the size of the forwarding belt associated with the last packaging machine to create a capacity for storing a certain amount of articles on the belt is also known. The forwarding belt can then be reversed when the personnel return, all the packaging machines are operational, and the last packaging machine ensures a reserve output while accepting no articles from the manufacturing machine, allowing the last packaging machine to accept articles from the intermediate-storage belt and package them. What is a drawback here is the small intermediate-storage capacity, which, in conjunction with a high-output manufacturing section will in some situations allow manufacturing to continue for only about one minute at any rate.
A buffer that operates on the principle of a vertical-chain conveyor and has a comparatively large capacity downstream of a packaging section is accordingly also known. A tower houses chain-driven buckets that accommodate the articles. The chains travel over a system of pulleys that move independently, and various numbers of articles can accordingly be added to and taken from the buckets at the same time. A bucket can only be unloaded of course when an associated packaging machine is operational. The exit from the tower usually communicates with a device that returns the stored objects to the packaging section, where they can be conveyed to a reserve output of operational packaging machines. The drawback of towers of this type is that they can usually be unloaded only by way of the last packaging machine, which takes a long time. The towers also have a limited capacity because they contain considerable amounts of mass that must be moved and do not allow all of the arriving articles to be accommodated. A tower of this type is accordingly not appropriate for covering periods in which all the packaging machines are down.
Positioning a central buffer of this kind at the upstream end of the packaging section, between the manufacturing machine and the first packaging machine, instead of at its downstream end, downstream of the packaging machines, that is, has already been proposed. This approach, however, entails the drawback that all the articles being packaged must travel through the buffer even though all or some of the packaging machines are in themselves operational. Forwarding the articles through a buffer when unnecessary again entails a basic drawback in that, when they are added to the buckets and removed from the bottom of the buckets, the articles move along the surface that they are resting on. A relative motion of this type is a drawback in that the articles will crumble to some extent, and buffers that all of the articles must travel through accordingly get dirty fairly rapidly. When the articles are elongated, they tend to tilt while being added to or removed from the buffer, no longer remaining oriented along the direction of travel, and it often becomes necessary to reorient them downstream of the buffer before they can be supplied to the individual packaging machines. Furthermore, an upstream central buffer of this type can only be employed with manufacturing sections that operate relatively slowly. The considerable masses that must be moved around inside the buffer prevent it from being loaded and unloaded rapidly.
Associating several small buffers instead of a single large one with the individual packaging machines in a packaging section has accordingly been proposed. The system is designed such that the articles constantly arriving on the continuous conveyor will be distributed among the individual buffers by complicated mechanisms. Each buffer is associated with one packaging machine, which can only be supplied from its particular buffer. The drawback of a packaging section of this type is that when one of the buffers malfunctions, its packaging machine will no longer be supplied with articles even though it is in itself operational. A packaging machine that is not operational on the other hand, because of a reel change for example, can cause a backup in the buffer just upstream, making it necessary to turn off the manufacturing machine because the buffer is full.